Ahum

Arjan, that 4M-ATX-HV item number sounds familiar to me, but I am not even responding to that at all. But about cars and boats, yes ...

Djeeeeeeeeeeeeeeeezzzzzzzzzzzzzzzzzzzzzzz

Freakin' stupid me only now recalls that he has 20 completely ready LPSU's for PC's in stock somewhere. Man, what a fool I am. Shiiiiiiiiiiit. Bought from a suspended railroad line something like 12 years ago. Think Orient Express but then from Holland (??) to Austria I think. Such an expensive line with all in there to enjoy yourself.

Envision :
Some trader offers 20 touch screen PC's (fairly rare at the time), completely custom built for that railroad and those PC's serving as point of sale terminals in the restaurant. PentiumIII I recall. Most of the screens were broken. PC cabinet (nice 30 degree or so upward touch screen) plus a 10-15Kg supply. I think there is something like a car battery in there.
So, we with a bunch of trolly's by elevator down to the car parking place (a garage) and it was totally crowded and I was waiting for ages until my wife came back with the car from the garage. The whole pavement filled with all this stuff and not in the most nice neighboorhoud (waiting to get robbed of the lot) - no idea yet how to ever get it in the car (but we managed).

The least I can do is finding out how this is all organized in these (two) cabinets and try to get it running for a normal PC ...

Peter

Hi,
I am still thinking of a test with a picoPsu and linear psu on my pc.
Searching the web I saw this product: 4M-ATX-HV. This is used to power computers on cars and boats. Might be interesting.
Regards

Hi Peter, the TV?, I bought it to watch the last soccer World Cup and I´m keeping it for the next one in Brasil hahaha.
Do you know with whom play Spain the first match, don´t you?. Good luck my friend. 

Seriously, I appreciate you are happy for me, I know it's a sincere feeling.

Hey Anthony, thank you for that effort;

It is a bit tough for me to decently reply to it, because it seems that you are on the right track with your perception of necessary recends (because of a higher transfer frequency ? <- I don't think so) while using an in my view unrelated article. All I can do is repeat my post about this, which doesn't seem much useful.

That article discusses jitter in a different fashion, because it compares the integrity of a signal (with itself) through an analyser which can be connected the wrong way. So, envsion the original signal (virtually on that scope) while it is compared with a degraded signal because of cable reflections and all mentioned there; It would show a false result only because of how the analyser is hooked up.
"Jitter" there is just used as delay, which in the end is a form of jitter.

Only when jitter gets that bad that not only the sample is captured too late (like for audio this will matter audibly) but that it is completely missed (crucial for your data send over the internet etc,), you can call jitter important up to devistating (but resends can recover the good signal assumed the errorneous receipt can be trapped); So this "digital jitter" (I'd like to call our audio phenomonen analog jitter) is quite crucial when very long distances are in order and it becomes easy miss complete "samples" because the jitter gets too bad.
Missed sample in THIS case : "Sampler" just reads signal, but signal is low again because too late while when it would have been in time it would have read a high (this is not 100% correct but gives the idea, especially emphasizing that such a thing NEVER will happen with audio <- haha  So, people often think that plain errors slip through and therefore wrong valued samples and such, but for audio it is not about that; only timing (when is this always good value put out up to the femto second). This not to be confused with my little subject of skipped samples because the OS thought it better cook an egg first.)

Peter

Hi,

This is a post that i’m really pleased to be making, there is a very nice gain in sound quality but I'v had a feeling that there should be a more consistent approach available to tuning the PC and NOS than I could find before.

What is here is the coming together of work on clocks, messings with BIOS settings and some help from the NEC USB chip datasheet the George posted a few days ago.

Lets start off with some sound quality characteristics that come about when tuning USB link clocks using the dexa "heavenly trimmer" haha (first touched on here  http://www.phasure.com/index.php?topic=2784.msg29143#msg29143)




So as the dexa usb clock speed at the PCIe USB card is tuned there are three sound quality conditions that occur:

1)   Sound characteristic 1 is super smooth, it sounds right and very appealing but when listened to you realise that dynamics / transients / weight / scale / and presence have suffered BUT the hardness in 2) has gone which is good.

2)   Sound characteristic 2 has a harsh element in the upper frequencies too much sibilance and on very complex passages particularly with lot of high frequency energy it feels loud in a poor sense.

3)   The “sweet spot”, sound characteristic 3 has smoothness and detail with good portrayal of dynamics / transients / weight / scale / and presence in addition there is detail but without the sibilance and harshness of case 2.
As you tune the dexa clock trimmer the tipping point to move from sound 1) to 2) via 3) (the sweet spot) is very rapid and takes a little work to find where sound 3 is to be found.




So far so good, some folks might recognise the sound types described. I have posted before on the CPU BIOS clock ratio setting and memory speed needing to be carefully set, on thinking these experiences and the dexa trimming about I was starting to see similarities in the sound types produced.

Then whist reading the NEC Data sheet that kindly George provided it was clear that data is being clocked in to the NEC chip from the PCIe bus which nominally runs at 100Mhz, hummmmm.....

So thoughts moved on, what if the main music data transition points can be tuned going backwards up the data stream from the NOS1 all the way back to the HDD, AND what if they behave in a similar way ? Now THAT would be something to work with ! -  a common principle that might be applicable to much of the PC and the USB link into the NOS.





So possible tuning points working back from the NOS upstream to the PC:

a)   PCIe USB clocl speed => NOS USB usb clock speed (using dexa clock trimmer on the PCIe USB card)

b)   PCIe bus speed => PCIe USB card clock speed (set using BIOS BCLK setting)

c)   CPU speed => PCIe bus speed (set using BIOS CPU ratio, (need an Extream mode lntel CPU for this) )

d)   RAM => CPU Speed (using BIOS Ram Speed setting)

So when tried the interesting thing is that each of the above four tuning points have exactly the same effect on sound. When the upstream side of the data transition is fast I get sound chrateristic no 1 when it is slow I get sound characteristic no 2 and then there is a knife edge transition setting which produces the sweet spot 3 in each case !

As an example a change in BIOS BCLK setting of less than 1% hops over the sweet spot setting from sound no 1 to sound no 2. In reality BCLK of 100mhz in BIOS = sound characteristic no 2 and Bios setting of 99.5mhz = sound characteristic no 3, the sweet spot, BCLK of 99mhz gives sound no2.

So I have spent  the afternoon messing about (being suppressed at the similarity of the effect of tuning each parameter) working from tuning points a) to d) above. At the end of this process sound is really excellent, better than I have heard before, silky smooth with ultra detail, coherent and with presence and scale tone and authority.

By a happy coincidence, last night I went to a carol concert at our town's cathedral to hear my daughter sing in a choir. It was a really nice evening but it also meant that I was listening to live church organ last night. Today with the tuning above the sound of reproduced church organ is very very close indeed to what I was hearing last night.





Settings on an ASRock z79 Extreme 4m mobo ended up as follows.

CPU BCLK = 99.5mhz
CPU ratio = 29
RAM 2100 Mhz
Dexa clock at the PCIe USB card 1/16th turn (about) clockwise from standard position (note running against a dexa set to standard trim position at the NOS USB interface.

Final thoughts.

I am strongly suspecting that the above may have something to do with any “wait state” that data encounters as it goes from one PC sub system to the next introducing jitter somehow. I'm also very excited about this, its the first time for me that a consistent approach applied to multiple points where speed can be tuned has resulted in totally consistent effects on sound quality.

Now I’m considering accelerating a project I have started to put a tuneable clock on a HDD, I know what I think it may do when tuned - but will it !! 

Best,

Nick.

Hey Anthony - I just ordered an SPL meter well I needed one anyway!

Paul

Quick question :

Can anyone (or everyone) describe what happened to the sound when Paul Pang's card was used instead of a normal NEC based USB3 card ?

I'm into the 5th track of "some" setup and ready to post about something strange and that maybe I found something ...

Peter